Neoplasia Lecture 1

NeoplasiaLecture 1

Dr. Maha ArafahFoundation block 2012

Pathology

Definition and Nomenculature

NeoplasiaUpon completion of these lectures, the student should: Define a neoplasm. Contrast neoplastic growth with

hyperplasia, metaplasia, and dysplasia. Know the basic principles of the nomenclature of benign

and malignant processes. Define and use in the proper context:

Adenoma. Papilloma. Polyp. Cystadenoma. Carcinoma. Adenocarcinoma. Sarcoma. Teratoma. Blastoma. Hamartoma.

Neoplasia Cancer is one of the leading causes

of death worldwide. Emotional and physical suffering by

the patient. Different mortality rate …..

Some are curable Others are fatal

Neoplasia Neoplasia = new growth Neoplasm = tumor Tumor = swelling The study of tumors = Oncology

Oncos = tumor + ology = study of

Neoplasia Definition:

is an abnormal mass of tissue, the growth of which is uncoordinated with

that of normal tissues, and that persists in the same excessive

manner after the cessation of the stimulus which evoked the change“

With the loss of responsiveness to normal growth controls

Different from hyperplasia, metaplasia and dysplasia.

Neoplasia Classification

Benign malignant

Neoplasia Benign tumors :

Will remain localized Cannot spread to distant sites Generally can be locally excised Patient generally survives

Neoplasia Malignant neoplasms:

Can invade and destroy adjacent structure

Can spread to distant sites Cause death (if not treated )

Neoplasia All tumors have two basic

components: Parechyma: made up of

neoplastic cells Stroma: made up of non-

neoplastic, host-derived connective tissue and blood vessels

The parenchyma:Determines the biological behavior of the tumorFrom which the tumor derives its name

The stroma:Carries the blood supplyProvides support for the growth of the parenchyma

Neoplasia Nomenclature

Benign tumors: prefix + suffix Type of cell + (-oma)

Neoplasia Examples:

Benign tumor arising in fibrous tissue: Fibro + oma = Fibroma

Benign tumor arising in fatty tissue: Lipo + oma = lipoma

Neoplasia Benign tumor arising in cartilage chondro + oma = chondroma Benign tumor arising in smooth

muscle Leiomyo + oma = leiomyoma Benign tumor arising in skeletal

muscle Rhabdomyo + oma = rhabdomyoma

Neoplasia epithelial benign tumors are

classified on the basis of : The cell of origin Microscopic pattern Macroscopic pattern

Neoplasia Adenoma : benign epithelial neoplasms

producing gland pattern….OR … derived from glands but not necessarily exhibiting gland pattern

Papilloma : benign epithelial neoplasms growing on any surface that produce microscopic or macroscopic finger-like pattern

Adenoma

Papilloma

Neoplasia Polyp : a mass that projects above a

mucosal surface to form a macroscopically visible structure.

e.g. - colonic polyp - nasal polyp

Polyp

Neoplasia Examples :

Respiratory airways: Bronchial adenoma

Renal epithelium: Renal tubular adenoma

Liver cell : Liver cell adenoma Squamous epithelium: squamous

papilloma

Neoplasia Malignant tumors:

Malignant tumor arising in mesenchymal tissue : SARCOMA

From fibrous tissue: Fibrosarcoma From bone : Osteosarcoma From cartilage : chondrosarcoma

Osteosarcoma

Neoplasia Malignant tumors arising from

epithelial origin : CARCINOMA Squamous cell carcinoma Renal cell adenocarcinoma cholangiocarcinoma

Carcinomas arising from any epithelium of the body that exhibit squamous differentiation are termed squamous cell carcinoma.

Nomenclatureother descriptive terms may be added such as:

Papillary Cystadenocarcinoma of the Ovary

NeoplasiaExceptions

Melanoma ( skin ) Mesothelioma (mesothelium ) Seminoma ( testis ) Lymphoma ( lymphoid tissue )

See table 6 – 1 page 168 ( Robbin’s )

Neoplasia Based on the biological behavior :

Benign and malignant

Based on the cell of origin : One neoplastic cell type : lipoma,

adenocarcinoma More than one neoplastic cell type :

fibroadenoma More than one neoplastic cell type

derived from more than one germ-cell layer: teratoma

Derived from embryonic tissue: blastoma (could be benign e.g. osteoblastoma, or malignant e.g. neuroblastoma)

Lipoma

Fibroadenoma

Teratoma

Neoplasia Teratoma:

Teratoma contains recognizable mature or immature cells or tissues representative of more than one germ-cell layer and some times all three.

Teratomas originate from totipotential cells such as those normally present in the ovary and testis.

Neoplasia Such cells have the capacity to

differentiate into any of the cell types found in the adult body. So they may give rise to neoplasms that mimic bone, epithelium, muscle, fat, nerve and other tissues.

Most common sites are: ovary & testis

Neoplasia If all the components parts are well

differentiated, it is a benign (mature) teratoma.

If less well differentiated, it is an immature (malignant) teratoma.

Neoplasia nomenclature- historic eponyms – “first described by…”

Malignant lymphoma (HL) of B Ly cell origin Hodgkin’s disease

NHL – B Ly cell in children (jaw and GIT) Burkitt tumor

Bone tumor (PNET) Ewing tumor

Kidney tumor - clear cell adenocarcinoma Grawitz tumor

Malignant tumor derived from vascular epithelium (AIDS)

Kaposi sarcoma

Ovarian tumor derived from Brenner cells Brenner tumor

Malignant chest wall tumor of PNET Askin tumor

Skin tumor derived from Merkel cell Merkel tumor

WHAT ARE HAMARTOMAS AND CHORISTOMA?

Hamartoma: a mass composed of cells native to the organ

e.g. pulmonary hamartoma.Choristoma: a mass composed of

normal cells in a wrong location e.g. pancreatic choristoma in liver

or stomach. Malformation and not neoplasm.

Pulmonary Hamartoma

Pancreatic choristoma in gall bladder

NeoplasiaHamartoma and Choristoma

They are distinguished from neoplasms by the fact that they do not exhibit continued growth. they are group of tumor-like tissue masses which may be confused with neoplasms